Incremental prognostic value of restrictive filling pattern in hypertrophic cardiomyopathy: a Doppler echocardiographic study

AIM: To study frequency and incremental prognostic value of restrictive filling pattern (RFP) in hypertrophic cardiomyopathy (HCM). METHODS AND RESULTS: Eighty-seven consecutive HCM patients (64% men, mean age 45 +/- 19 years) underwent physical and Doppler echocardiographic evaluation at our centre from March 1993 to February 2001. Mean length of follow-up was 96 +/- 54 months. RFP was found in 14 patients (16%) at index evaluation. Patients with RFP had higher NYHA class, more frequent signs of heart failure and lower left ventricular ejection fraction (P = 0.018, P = 0.002 and P = 0.001, respectively). During follow-up, cardiac death plus heart transplantation was significantly higher in HCM patients with RFP than in those without RFP (P = 0.0001). NYHA class (HR = 5.95, 95% CI: 1.34-26.38, P = 0.019), indexed left atrial diameter (HR = 1.68, 95% CI: 1.01-2.82, P = 0.047) and RFP (HR = 2.94, 95% CI: 1.25-6.88, P = 0.01) were selected as predictors of cardiac death or heart transplantation in a multivariate proportional hazard model. The AUC of ROC curve from multivariate regression models for predicting adverse outcome significantly improved from 0.76 considering only NYHA class to 0.84 after inclusion of RFP and indexed left atrial diameter (P = 0.01). CONCLUSIONS: RFP is rare, but not exceptional, in HCM. Echo-Doppler evaluation of filling pattern confers additional prognostic power to clinical stratification.